A conventional garbage disposer comprises a catalyst to eliminate odor, oil and smoke generated when the garbage is heated. Such conventional garbage disposer is configured as shown in FIG. 12 and FIG. 13. The description of a conventional garbage disposer will be given in the following.
As shown in FIG. 12, garbage disposer main body 121 comprises a storage section 122, rotary shaft 123, stirring blade 124, heating means 125, deodorizer 137, exhaust fan 134, and drive motor 135.
The garbage is stored in the storage section 122. The rotary shaft 123 is disposed nearly at the center of the storage section 122, and the stirring blade 124 is fixed on the rotary shaft 123. The heating means 125 is installed on top of the storage section 122 to heat the garbage. The heating means 125 has a drying heater 126 and a drying fan 127. The drying fan 127 applies hot air to the garbage, thereby heating the surfaces of the garbage. The drying fan 127 is driven by drying motor 128. An intake passage 103 and exhaust passage 136 are connected to the storage section 122, and the deodorizer 137 is disposed between the intake passage 103 and the exhaust passage 136. The deodorizer 137 comprises a metallic pipe 101, fin 102, catalyst, and catalyst heater 108 as shown in FIG. 13. The fin 102 is formed with a band metal sheet spirally wound around the metallic pipe 101. The catalyst is held to the fin 102. The catalyst heater 108 is disposed in the metallic pipe 101. When the catalyst is heated by the catalyst heater 108, the odor substance is oxidized and decomposed. Intake port 133 is formed at the top of the storage section 122. The exhaust fan 134 is disposed at the rear of the exhaust passage 136. The drive motor 135 serves to drive the rotary shaft 123.
In such conventional type garbage disposer, when the garbage disposer 121 is operated, the catalyst is heated by the catalyst heater 108 in the deodorizer 137. When the exhaust fan 134 is operated, air is taken in from the intake port 133. The air that contains odor in the storage section 122 is deodorized by the deodorizer 137, and the deodorized air is exhausted outside.
However, in such conventional garbage disposer, to improve the purifying capacity of the deodorizer 137, it is necessary to increase the number of turns of the fin 102. In case of a great many turns of the fin 102, the pressure loss will increase while the exhaust gas flows in the fin 102, affecting the smooth flow of the exhaust gas.
Also, as an another method of improving the purifying capacity, it is possible to increase the surface area of the fin 102. However, when the fin 102 is formed by spirally winding band metal sheet around the metallic pipe 101, it is necessary to make creases (not shown) on the inner diameter portion of the spiral fin 102 contacting with the metallic pipe 101. When the fin 102 is increased in outer diameter in order to increase the surface area of the fin 102, deeper creases will be formed thereon. Accordingly, the fin 102 cannot be manufactured. Also, in case the fin 102 is larger in outer diameter, it is difficult to make the circumference of the spiral fin 102 uniformly circular. Therefore, the spiral fin 102 cannot be enlarged in outer diameter.